Positive and negative magnetoresistance phenomena observed in magnetic electrospun polyacrylonitrile-based carbon nanocomposite fibers

Unique temperature dependent resistance behavior (positive/negative temperature coefficient switching at 240 K), and tunable negative and positive magnetoresistance switching phenomena were observed in the magnetic carbon nanocomposite fibers prepared from heat treatment of the nitrate soaked oxidation stabilized polyacrylonitrile (PAN) nanofibers. The physical mechanisms were revealed by considering the variable range hopping electron transportation model, electron quantum interference and spin-dependent scattering effects. © 2013 The Royal Society of Chemistry